The present invention relates to an idle speed controller for internal combustion engine, in particular, an idle speed controller having enhanced stability of flow rate control.
Conventionally, an idle speed controller comprises a solenoid coil assembly fitted in an inner peripheral portion of a solenoid case, and a guide plate press fitted in another inner peripheral portion of the solenoid case. The solenoid case is crimped to a valve body, and the guide plate serving as a sliding guide for a valve shaft to a plunger is independent from the solenoid coil assembly. In other words, the solenoid coil assembly and the guide plate are never directly connected.
These idle speed controllers are problematic because the dimensional tolerances of the component parts accumulate to lower the accuracy of the central axis between the sliding valve shaft and the electromagnetic solenoid plunger. Thus, the control of an opening area of an orifice formed at the tip of the valve shaft becomes highly unstable. Consequently, flow rate control is hard to regulate.
An object of the present invention is to provide an idle speed controller for internal combustion engine having enhanced stability of flow rate control.
In an object of the present invention an idle speed controller is provided comprising a valve portion comprising a shaft for intake of auxiliary air and a solenoid portion comprising a plunger for driving the shaft and a solenoid coil assembly having a plunger guide portion for guiding the plunger, the assembly further comprising a cylindrical projected portion. The invention further provides a guide plate having a spigot portion fixedly attached to the cylindrical projected portion of the assembly and a shaft guide portion for guiding the shaft wherein a symmetrical central axis is maintained between the shaft and the plunger.
In another object of the present invention an idle speed controller is provided comprising a guide plate having a spigot portion fixedly attached to a cylindrical projected portion of a solenoid coil assembly for guiding a shaft to and away from a plunger wherein a symmetrical central axis is maintained between the shaft and the plunger during the guiding of the shaft.
In another object of the present invention an idle speed controller is provided comprising a guide plate having a spigot portion fixedly attached to a cylindrical projected portion of a solenoid coil assembly for guiding a valve portion to and away from a solenoid portion wherein a symmetrical central axis is maintained between the valve portion and the solenoid portion during the guiding of the valve portion.
In yet another object of the present invention an idle speed controller is provided comprising a valve portion comprising a shaft for intake of auxiliary air, a solenoid portion comprising a plunger for driving the shaft and a solenoid coil assembly having a plunger guide portion for guiding the plunger, the assembly further comprising a cylindrical projected portion. The invention further provides a guide plate having a spigot portion fixedly attached to the cylindrical projected portion of the assembly and a shaft guide portion for guiding the shaft wherein a symmetrical central axis is maintained between the shaft and the plunger wherein an O-ring is provided in the spigot portion.
In another object of the present invention an idle speed controller is provided comprising a guide plate having a spigot portion fixedly attached to a cylindrical projected portion of a solenoid coil assembly for guiding a valve portion to and away from a solenoid portion wherein a symmetrical central axis is maintained between the valve portion and the solenoid portion during the guiding of the valve portion. The invention further provides a solenoid case having a first flange portion in the solenoid portion, a valve body having a second flange portion in the valve portion wherein the guide plate further comprising a third flange portion and the flange portions are all crimped together.
In another object of the present invention a method of manufacturing an idle speed controller is provided comprising the steps of providing a valve portion comprising a shaft for intake of auxiliary air and providing a solenoid portion comprising a plunger for driving the shaft and a solenoid coil assembly having a plunger guide portion for guiding the plunger, the assembly further comprising a cylindrical projected portion. The method further provides the step of fixedly attaching a guide plate having a spigot portion to the cylindrical projected portion of the assembly and a shaft guide portion for guiding the shaft wherein a symmetrical central axis is maintained between the shaft and the plunger.
In another object of the present invention a method of manufacturing an idle speed controller is provided comprising the steps of fixedly attaching a guide plate having a spigot portion to a cylindrical projected portion of a solenoid coil assembly for guiding a shaft to and away from a plunger wherein a symmetrical central axis is maintained between the shaft and the plunger during the guiding of the shaft.
In another object of the present invention a method of manufacturing an idle speed controller is provided comprising the steps of fixedly attaching a guide plate having a spigot portion to a cylindrical projected portion of a solenoid coil assembly for guiding a valve portion to and away from a solenoid portion wherein a symmetrical central axis is maintained between the valve portion and the solenoid portion during the guiding of the valve portion.
In yet another object of the present invention a method of manufacturing an idle speed controller is provided comprising the steps of providing a valve portion comprising a shaft for intake of auxiliary air and providing a solenoid portion comprising a plunger for driving the shaft and a solenoid coil assembly having a plunger guide portion for guiding the plunger, the assembly further comprising a cylindrical projected portion. The method further includes the steps of fixedly attaching a guide plate having a spigot portion to the cylindrical projected portion of the assembly and a shaft guide portion for guiding the shaft wherein a symmetrical central axis is maintained between the shaft and the plunger wherein an O-ring is provided in the spigot portion.
In another object of the present invention a method of manufacturing an idle speed controller is provided comprising the steps of fixedly attaching a guide plate having a spigot portion to a cylindrical projected portion of a solenoid coil assembly for guiding a valve portion to and away from a solenoid portion wherein a symmetrical central axis is maintained between the valve portion and the solenoid portion during the guiding of the valve portion. The method further provides the steps of providing a solenoid case having a first flange portion in the solenoid portion and providing a valve body having a second flange portion in the valve portion wherein the guide plate further comprising a third flange portion and crimping the flange portions together.